This invention relates to magnetic recording apparatus, and is more particularly directed to magnetic recording apparatus of reduced size which is suitable for use in a miniature video tape recorder, for example, in a combination television camera and video tape recorder formed as a unit.
A helical scan type video tape recorder (VTR) suitable, for example, for home use (referred to hereinafter as a standard VTR) is usually arranged to have video tape wrapped about a guide drum thereof for a wrap angle (i.e., a circumferential angle of the drum) of substantially 180.degree.. A pair of magnetic heads are spaced 180.degree. apart on the guide drum, and are used alternately to record the video signal in successive slant tracks on the tape. The magnetic heads are also used to pick up the video signal from recorded slant tracks on the tape. The tape is wrapped about the head drum at a so-called still angle relative to the plane of the magnetic heads about the drum.
Because the pattern of the recorded slant tracks depends on the wrap angle and the still angle of the tape wrapped about the drum, and also on the diameter of the drum, it follows that if the wrap angle is increased and the still angle changed, the diameter of the guide drum can be reduced, and the overall dimensions of the VTR can be reduced accordingly.
For example, if the wrap angle is increased from 180.degree. to 300.degree. and recording and playback of the video signal are carried out using a single rotary magnetic head, a reduced-diameter drum can be used, with a diameter only about 3/5 that of the standard VTR guide drum.
However, if such a reduced-diameter head drum is used, the resulting pattern of recorded slant tracks will be different from the pattern used with a standard VTR. Hence, prior proposals for miniature VTRs have been unable to use reduced-diameter head drums to record video signals on tape so that the signals could be readily picked up by playing the tape on a standard VTR. Conversely, tapes recorded on a standard VTR could not be played back on a previous miniature VTR having a reduced-diameter drum.